1. Field of the Invention
The invention relates to an air duct for forming an air path in a space inside electronic equipment, particularly, an air duct having a structure which is easily disassembled and assembled and electronic equipment using the air duct.
2. Description of the Related Art
Heat radiation and cooling in electronic equipment are conventionally indispensable to prevent the deterioration and keep stability and reliability of the operation of the electronic equipment. A cooling fan has been generally used for cooling the electronic equipment, and heating portion such as heating components and the like is cooled by air which is taken in the electronic equipment. For example, if a cooling fan is installed at the rear panel side to exhaust air, cooling air is sucked from the front panel side and so forth into the electronic equipment and it flows in the electronic equipment so that the heating portion is cooled by the cooling air which passes in the electronic equipment.
There are prior art patent references for disclosing a technique relating to an attachment structure and a cooling structure of a cooling fan of electronic equipment such as U.S. Pat. No. 5,473, 507, JP-A 05-251875, JP-A 2000-22375, JP-A 2000-323878 and so forth.
U.S. Pat. No. 5,473,507 and JP-A 05-251875 disclose electronic equipment, wherein the electronic equipment and a chassis for installing the electronic equipment are respectively made of a plastic material and an air duct is formed by the chassis and so forth for supplying cooling air to electronic elements to be cooled. The JP-A 2000-22375 discloses a fixture structure of the fan unit in which the replacement of the fan unit is made easily when it is troubled. JP-A 2000-323878 discloses a cooling structure of electronic equipment comprising a housing of the electronic equipment and a frame body formed of an elastic member disposed between the housing and a sealed case which is disposed in the housing, thereby forming a wind tunnel serving as a cooling duct.
Meanwhile, with the technique disclosed in U.S. Pat. No. 5,473,507 and JP-A 05-251875, the chassis for mounting components of the electronic equipment and so forth on a housing of the electronic equipment is formed of the plastic material and the components are mounted on the chassis. The chassis has a ventilator for drawing air from the outside at the position corresponding to a wind tunnel slot of a front face cover, and the cooling air current produced in the chassis by the ventilator passes from the opening of the chassis, through the opening of the back face plate and a slit of a back face cover plate, and flows outside. That is, the structure for supplying the cooling air current by the chassis and ventilator to the components to be cooled is the same as the cooling structure of the conventional electronic equipment, and the difference therebetween resides in whether the chassis is formed of metal or plastic material. Further, with such a chassis structure, it is not possible to design the air duct and the housing separately from each other so that they can not be assembled or disassembled. Replacement of the ventilator requires an operation for removing the front cover plate and the front face sealed plate, then removing a metallic enclosure enclosing the chassis, and separating the upper portion from the lower portion of the chassis, which is very troublesome and takes labor.
Further, with the technique disclosed in JP-A 2000-22375, it merely discloses a fixture structure of a fan unit, which cannot constitute an air duct inside the electronic equipment.
Still further, with the technique disclosed in JP 2000-323878A, a circuit board is installed in a space enclosed by a chassis and a top plate, and a fan is installed on a ceiling part of a sealed case covering the upper face part of the circuit board, and wherein cooling air is sucked from a bottom face side of the sealed case, then it is allowed to pass through heating components on the circuit board, thereafter it is allowed to flow out from a heat radiating holes of the top plate, thereby cooling the circuit board enclosed by the chassis, the top plate and the sealed case. This technique is however discloses that the chassis per se is merely rendered to be air duct, and an air duct is not formed relative to a specific component, and the replacement of a fan requires the operation for removing the top plate from the chassis and removing the sealed case from the chassis, which is very troublesome and takes labor.